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Aluminium in the North Atlantic Ocean and the Labrador Sea (GEOTRACES GA01 section): roles of continental inputs and biogenic particle removal 5
Barraqueta, Jan-lukas Menzel; Schlosser, Christian; Planquette, Helene; Gourain, Arthur; Cheize, Marie; Boutorh, Julia; Shelley, Rachel; Pereira, Leonardo Contreira; Gledhill, Martha; Hopwood, Mark J.; Lacan, Francois; Lherminier, Pascale; Sarthou, Geraldine; Achterberg, Eric P..
The distribution of dissolved aluminium (dAl) in the water column of the North Atlantic and Labrador Sea was studied along GEOTRACES section GA01 to unravel the sources and sinks of this element. Surface water dAl concentrations were low (median of 2.5 nM) due to low aerosol deposition and removal by phytoplankton. However, surface water dAl concentrations were enhanced on the Iberian and Greenland shelves (up to 30.9 nM) due to continental inputs (rivers, glacial flour and ice melt). A negative correlation was observed between dAl in surface waters and primary production, phytoplankton community structure and biogenic opal production. The abundance of diatoms exerted a significant (p < 0.01) control on the surface particulate Al (pAl) to dAl ratios by...
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00422/53359/54197.pdf
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Contribution of resuspended sedimentary particles to dissolved iron and manganese in the ocean: An experimental study 5
Cheize, Marie; Planquette, H.f.; Fitzsimmons, J.n.; Pelleter, Ewan; Sherrell, R.m.; Lambert, Christophe; Bucciarelli, E.; Sarthou, G.; Le Goff, Marion; Liorzou, Celine; Chéron, Sandrine; Viollier, E.; Gayet, Nicolas.
A number of trace metals play essential roles in marine ecosystem structure and biological productivity. Until recently, it has been argued that phytoplankton access primarily dissolved iron, while particulate iron was considered a refractory material with little use biologically and limited interaction with the dissolved pool. In order to assess the transfer mechanisms between sediment-sourced particulate trace metals and the dissolved pool, we conducted a 14-month incubation that reacted resuspended sediments with natural seawater, both originating from the Kerguelen area (KEOPS cruises; Southern Ocean), in the dark, and at concentrations replicating natural conditions. Three types of sediments were investigated (named BioSi, BioSi + Ca, and Basalt),...
Tipo: Text Palavras-chave: Suspended particle dissolution; Sediment; Iron; Manganese; Biogenic silica; Southern Ocean; Kerguelen.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00460/57197/59166.pdf
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Dissolved iron in the North Atlantic Ocean and Labrador Sea along the GEOVIDE section (GEOTRACES section GA01) 5
Tonnard, Manon; Planquette, Hélène; Bowie, Andrew R.; Van Der Merwe, Pier; Gallinari, Morgane; Desprez De Gésincourt, Floriane; Germain, Yoan; Gourain, Arthur; Benetti, Marion; Reverdin, Gilles; Tréguer, Paul; Boutorh, Julia; Cheize, Marie; Menzel Barraqueta, Jan-lukas; Pereira-contreira, Leonardo; Shelley, Rachel; Lherminier, Pascale; Sarthou, Géraldine.
Dissolved Fe (DFe) samples from the GEOVIDE voyage (GEOTRACES GA01, May–June 2014) in the North Atlantic Ocean were analysed using a SeaFAST-picoTM coupled to an Element XR HR-ICP-MS and provided interesting insights on the Fe sources in this area. Overall, DFe concentrations ranged from 0.09 ± 0.01 nmol L−1 to 7.8 ± 0.5 nmol L−1. Elevated DFe concentrations were observed above the Iberian, Greenland and Newfoundland Margins likely due to riverine inputs from the Tagus River, meteoric water inputs and sedimentary inputs. Air-sea interactions were suspected to be responsible for the increase in DFe concentrations within subsurface waters of the Irminger Sea due to deep convection occurring the previous winter, that provided iron-to-nitrate ratios sufficient...
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Ano: 2020 URL: https://archimer.ifremer.fr/doc/00441/55233/56714.pdf
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Dissolved Pb and Pb isotopes in the North Atlantic from the GEOVIDE transect (GEOTRACES GA-01) and their decadal evolution 5
Zurbrick, Cheryl M.; Boyle, Edward A.; Kayser, Richard J.; Reuer, Matthew K.; Wu, Jinfeng; Planquette, Helene; Shelley, Rachel; Boutorh, Julia; Cheize, Marie; Contreira, Leonardo; Barraqueta, Jan-lukas Menzel; Lacan, Francois; Sarthou, Geraldine.
During the 2014 GEOVIDE transect, seawater samples were collected for dissolved Pb and Pb isotope analysis. These samples provide a high-resolution "snapshot" of the source regions for the present Pb distribution in the North Atlantic Ocean. Some of these stations were previously occupied for Pb from as early as 1981, and we compare the 2014 data with these older data, some of which are reported here for the first time. Lead concentrations were highest in subsurface Mediterranean Water (MW) near the coast of Portugal, which agrees well with other recent observations by the US GEOTRACES program (Noble et al., 2015). The recently formed Labrador Sea Water (LSW) between Greenland and Nova Scotia is much lower in Pb concentration than the older LSW found in...
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00456/56760/58607.pdf
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Ecophysiological and metabolic adaptations to sulphide exposure of the oyster Crassostrea gigas 5
Le Moullac, Gilles; Cheize, Marie; Gastineau, Olivier; Daniel, Jean-yves; Le Coz, Jean-rene; Huvet, Arnaud; Moal, Jeanne; Pouvreau, Stephane; Van Wormhoudt, A; Samain, Jean-francois.
The purpose of this study is to examine the response of the oyster Crassostrea gigas to sulphide at different biological scales. A first experiment was designed to measure for 20 h the clearance (CR) and oxygen consumption (OC) rates of oysters exposed at different concentrations of sulphide (0, 3, 6, 12, 20, and 40 mu M). The second experiment was carried out to evaluate the metabolic adaptations to chronic sulphide exposure for 10 days by measuring PK and PEPCK enzyme activities, succinate and alanine content, the adenylate energy charge (AEC), and the activity of the electron transport system (ETS)in whole oysters at above 20 mu M. PK and PEPCK mRNAs and enzyme activities have been measured in adductor muscle. When exposed to sulphide above 20 mu M, CR...
Tipo: Text Palavras-chave: ATP; AEC; Electron transport system; Succcinate; Alanine; Phosphoenolpyruvate carboxykinase; Pyruvate kinase; Oxygen consumption; Clearance rate; Crassostrea gigas; Sulphide; Oyster.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/publication-3924.pdf
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High variability in dissolved iron concentrations in the vicinity of the Kerguelen Islands (Southern Ocean) 5
Queroue, Fabien; Sarthou, Geraldine; Planquette, Helene; Bucciarelli, Eva; Chever, Fanny; Van Der Merwe, P.; Lannuzel, Delphine; Townsend, A. T.; Cheize, Marie; Blain, S.; D'Ovidio, F.; Bowie, A. R..
Dissolved Fe (dFe) concentrations were measured in the upper 1300 m of the water column in the vicinity of the Kerguelen Islands as part of the second KErguelen Ocean Plateau compared Study (KEOPS2). Concentrations ranged from 0.06 nmol L-1 in offshore, Southern Ocean waters to 3.82 nmol L-1 within Hillsborough Bay, on the north-eastern coast of the Kerguelen Islands. Direct island runoff, glacial melting and resuspended sediments were identified as important inputs of dFe that could potentially fertilise the northern part of the plateau. A significant deep dFe enrichment was observed over the plateau with dFe concentrations increasing up to 1.30 nmol L-1 close to the seafloor, probably due to sediment resuspension and pore water release. Biological uptake...
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Ano: 2015 URL: https://archimer.ifremer.fr/doc/00274/38482/36942.pdf
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Inputs and processes affecting the distribution of particulate iron in the North Atlantic along the GEOVIDE (GEOTRACES GA01) section 5
Gourain, Arthur; Planquette, Helene; Cheize, Marie; Lemaitre, Nolwenn; Menzel Barraqueta, Jan-lukas; Shelley, Rachel; Lherminier, Pascale; Sarthou, Geraldine.
The GEOVIDE cruise (May–June 2014, R/V Pourquoi Pas?) aimed to provide a better understanding on trace metal biogeochemical cycles in the North Atlantic. As particles play a key role in the global biogeochemical cycle of trace elements in the ocean, we discuss the distribution of particulate iron (PFe), in light of particulate aluminium (PAl), manganese (PMn) and phosphorus (PP) distributions. Overall, 32 full vertical profiles were collected for trace metal analyses, representing more than 500 samples. This resolution provides a solid basis for assessing concentration distributions, elemental ratios, size-fractionation, or adsorptive scavenging processes in key areas of the thermohaline circulation. Total particulate iron (PFe) concentrations ranged from...
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Ano: 2019 URL: https://archimer.ifremer.fr/doc/00485/59676/62747.pdf
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Introduction to the French GEOTRACES North Atlantic Transect (GA01): GEOVIDE cruise 5
Sarthou, Geraldine; Lherminier, Pascale; Achterberg, Eric P.; Alonso-perez, Fernando; Bucciarelli, Eva; Boutorh, Julia; Bouvier, Vincent; Boyle, Edward A.; Branellec, Pierre; Carracedo, Lidia I.; Casacuberta, Nuria; Castrillejo, Maxi; Cheize, Marie; Pereira, Leonardo Contreira; Cossa, Daniel; Daniault, Nathalie; De Saint-leger, Emmanuel; Dehairs, Frank; Deng, Feifei; De Gesincourt, Floriane Desprez; Devesa, Jeremy; Foliot, Lorna; Fonseca-batista, Debany; Gallinari, Morgane; Garcia-ibanez, Maribel I.; Gourain, Arthur; Grossteffan, Emilie; Hamon, Michel; Heimburger, Lars Eric; Henderson, Gideon M.; Jeandel, Catherine; Kermabon, Catherine; Lacan, Francois; Le Bot, Philippe; Le Goff, Manon; Le Roy, Emilie; Lefebvre, Alison; Leizour, Stephane; Lemaitre, Nolwenn; Masque, Pere; Menage, Olivier; Barraqueta, Jan-lukas Menzel; Mercier, Herle; Perault, Fabien; Perez, Fiz F; Planquette, Helene; Planchon, Frederic; Roukaerts, Arnout; Sanial, Virginie; Sauzede, Raphaelle; Schmechtig, Catherine; Shelley, Rachel U.; Stewart, Gillian; Sutton, Jill; Tang, Yi; Tisnerat-laborde, Nadine; Tonnard, Manon; Treguer, Paul; Van Beek, Pieter; Zurbrick, Cheryl M.; Zunino Rodriguez, Patricia.
The GEOVIDE cruise, a collaborative project within the framework of the international GEOTRACES programme, was conducted along the French-led section in the North Atlantic Ocean (Section GA01), between 15 May and 30 June 2014. In this special issue (https://www.biogeosciences.net/special_ issue900.html), results from GEOVIDE, including physical oceanography and trace element and isotope cyclings, are presented among 18 articles. Here, the scientific context, project objectives, and scientific strategy of GEOVIDE are provided, along with an overview of the main results from the articles published in the special issue.
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00470/58178/60685.pdf
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Mercury distribution and transport in the North Atlantic Ocean along the GEOTRACES-GA01 transect 5
Cossa, Daniel; Heimburger, Lars-eric; Perez, Fiz F; Garcia-ibanez, Maria Isabel; Sonke, Jeroen E.; Planquette, Helene; Lherminier, Pascale; Boutorh, Julia; Cheize, Marie; Barraqueta, Jan Lukas Menzel; Shelley, Rachel; Sarthou, Geraldine.
We report here the results of total mercury (HgT) determinations along the 2014 GEOTRACES GEOVIDE cruise (GA01 transect) in the North Atlantic Ocean (NA) from Lisbon (Portugal) to the Labrador coast (Canada). Ninety-seven percent of the HgT concentrations of unfiltered samples (HgTUNF) ranged between 0.16 and 1.00 pmol L−1. The geometric mean was 0.51 pmol L−1 for the 535 samples analysed. The dissolved fraction (< 0.45 μm) of HgT, determined on 141 samples, averaged 78 % of the HgTUNF for the whole water column. HgTUNF concentrations increased eastwards and with depth from Greenland to Europe and from sub-surface to bottom waters, respectively. The Hg distribution mirrored that of dissolved oxygen concentration, with highest HgTUNF levels associated...
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00412/52303/53071.pdf
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Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic 5
Lemaitre, Nolwenn; Planquette, Helene; Planchon, Frederic; Sarthou, Geraldine; Jacquet, Stephanie; Garcia-ibanez, Maria Isabel; Gourain, Arthur; Cheize, Marie; Monin, Laurence; Andre, Luc; Laha, Priya; Terryn, Herman; Dehairs, Frank.
The remineralisation of sinking particles by prokaryotic heterotrophic activities is important for controlling oceanic carbon sequestration. Here, we report mesopelagic particulate organic carbon (POC) remineralisation fluxes in the North Atlantic along the GEOTRACES-GA01 section (GEOVIDE cruise; May–June 2014) using the particulate biogenic barium (excess barium; Baxs) proxy. Important mesopelagic (100–1000 m) Baxs differences were observed along the transect depending on the intensity of past blooms, the phytoplankton community structure and the physical forcing, including downwelling. The subpolar province was characterized by the highest mesopelagic Baxs content (up to 727 pmol L−1), which was attributed to an intense bloom averaging 6 mg Chl-a m−3...
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Ano: 2018 URL: https://archimer.ifremer.fr/doc/00412/52308/53075.pdf
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Processes Driving Iron and Manganese Dispersal From the TAG Hydrothermal Plume (Mid-Atlantic Ridge): Results From a GEOTRACES Process Study 5
González-santana, David; Planquette, Helene; Cheize, Marie; Whitby, Hannah; Gourain, Arthur; Holmes, Thomas; Guyader, Vivien; Cathalot, Cecile; Pelleter, Ewan; Fouquet, Yves; Sarthou, Geraldine.
Hydrothermal vents are a recognized source of trace elements to the ocean inventory. Nevertheless, the contribution of slow-spreading ridges remains poorly resolved. To address this, high-resolution dissolved (<0.45 μm) iron (dFe) and manganese (dMn) samples were collected during the GEOTRACES HERMINE GApr07 process study at the Mid Atlantic Ridge. Samples were collected at nine stations, from the TAG vent site to 75 km south-southwest following the neutrally buoyant plume. Concentrations of dMn and dFe ranged from 71 ± 6 and 51 ± 2 nmol kg–1 right above the vent site to 0.43 ± 0.01 and 1.56 ± 0.02 nmol kg–1 at the most distal station, respectively. Using a 5-box model coupled with our data, we show that as the plume traveled away from the vent,...
Tipo: Text Palavras-chave: Iron; Manganese; Hydrothermal; TAG; Mid Atlantic Ridge; GEOTRACES.
Ano: 2020 URL: https://archimer.ifremer.fr/doc/00643/75530/76431.pdf
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Trace element and isotope deposition across the air-sea interface: progress and research needs 5
Baker, A. R.; Landing, W. M.; Bucciarelli, E.; Cheize, Marie; Fietz, S.; Hayes, C. T.; Kadko, D.; Morton, P. L.; Rogan, N.; Sarthou, G.; Shelley, R. U.; Shi, Z.; Shiller, A.; Van Hulten, M. M. P..
The importance of the atmospheric deposition of biologically essential trace elements, especially iron, is widely recognized, as are the difficulties of accurately quantifying the rates of trace element wet and dry deposition and their fractional solubility. This paper summarizes some of the recent progress in this field, particularly that driven by the GEOTRACES, and other, international research programmes. The utility and limitations of models used to estimate atmospheric deposition flux, for example, from the surface ocean distribution of tracers such as dissolved aluminium, are discussed and a relatively new technique for quantifying atmospheric deposition using the short-lived radionuclide beryllium-7 is highlighted. It is proposed that this field...
Tipo: Text Palavras-chave: Air-sea exchange; Atmospheric deposition; Trace element solubility; Biogeochemical impacts; Mineral dust; Anthropogenic aerosols.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00369/48045/48131.pdf
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